Process of dyeing



Patented Mar. 2, 1926.

UNITED STATES PATENT OFFICE.

WALTER DUISBERG AND WINFRIED HENTRICH, 0F WIESDORF-ON-THE-RHINE, GER- MANY, ASSIGNORS TO THE GRASSELLI 'DYESTUFF CORPORATION, OF NEW YORK,

PROCESS OF DYEING.

To all whom it may concern:

Be it known that we, \VAL'rEn Dmsnnno and Vmrnmo HEN'IRTCH, citizens of Germany, residing at \Viesdorf-on-the-Rhine, State of Prussia, Germany, have invented new and useful Improvements in Processes of Dyeing, of which the following is a specifieation.

We have found new and useful improvements in processes of dyeing cellulose esters and cellulose ethers.

This invention relates to the production of dyed cellulose products such as are ob tained from cellulose esters and cellulose others, i. e., cellulose acetate silks, films made out of cellulose acetate or ethylcellulose, etc.

Whereas most mono azo colors have practically no aflinity for such cellulose derivatives, we have found that very strong, deep and fast shades can be obtained on organooxy-cellulose compounds, if such material is dyed with azo colors such as are obtained by combiningan acid substituted aromatic nitro diazo compound with an aromatic amine. For the purpose of this invention the term organo-oxy-cellulose compound is understood to cover organic cellulose esters such as cellulose acetate, cellulose formate, cellulose butyrateyetc. and cellulose ethers such as methyl cellulose, ethyl cellulose, etc.

By varying the components in the dyestulis to be used for our dyeing process all.

possible shades ranging from light pink to violet blue, brown, etc. can be obtained.

Amongst the diazo compounds used in the production of our dyes we mention 2'diazo- 4-nitro-benzoic acid, l-diazo-Q-nitro-d-sulionic-acid, 1-diazo-4-nitro-2sulfonic acid, 2- diazo-5-nitr0-l-phenol-ether--sulfonic acid, etc. Some of the coupling compounds that can be used are: on and B naphthylamine, N substituted naphthylamines, amide naphthols, etc.

The diazo compounds mentioned have the following formulae:

Q-diazo-d-nitro-benzoic acid:

coon

Application filed November 26, 1924. Serial No. 752,457.

1-diazo-2-nitroA-sulfonic acid:

N=NCl SOaH l-diazoA-nitro-2-sulfonic acid:

N=NC1 J SOaH 2-diazo-5-nitro-l-phenol-ether 4J-sulfonie acid SOaH Emample.

Two parts of the dyestufi' l-nitro-l-benzoate. o1: soda-2-azometh lbenzylaniline are dissolved in 100 parts of lot water. 25 parts of cellulose acetate threads are entered at about 70 C. and dyed for 7 hour. The

hanks are squeezed and dried in the usual way. Clear orange shades are obtained.

The dyestufl' 2-nitro-4-sulfobenzene-l-azoethyl-,8 naphthylanaine dyed in a similar way produces bluish pink shades on cellulose acetate, other shades are obtained as follows:

et-nitro-2-sulfobenzene-1-azoethyl-B naphthylamine dyes deep violet, 2-6-dinitro ben zene 4 sulfo l-azo-ethyl-a naphthylamine dyes violet, 5-nitro-4-sulfo-l-phenylether-Q- azo-L5-amido-naphthol combined in an acid medium gives blue shades.

The formulae of the dyestuffs referred to in the foregoing example are as follows:

-nitro-l-benzoate of soda-2-azo-methyl benzylaniline COONa CH1 N=N N 2 nitro 4 sulfo benzene-l-azo-ethyl-B naphthylamine 4-nitro-2-sulfobenzene-l-azo-ethyl-fi-naph- 'thylamine SOaNa 2.6-dinitro benzene-et-sulfo-l-azo-ethyl-anaphthylamine:

GB No: i I NO OaNa 5 nitro 4-sulfo-l-phenylethcr-2-azo-1.5- amino-naphthol 1. The process of dyeing organo-oxy-cellulose compounds which comprises applying thereto dyestufi's of the type R-NzN-R in which RN::N stands for the diazo derivative of an acid substituted aromatic nitro compound and R stands for an aromatic amine.

2. The process of dyeing organo-oxy-ceL lulose compounds which comprises applying thereto dyestuffs of the type R-N:NR'

in which RN:N represents the diazo derivative of an acid substituted nitrobenzene compound and R represents an aromatic amine.

3. The process of dyeing organo-oxy-cellulose compounds which comprises applying thereto dyestufi's of the type R-N:N-R in which R-N:N- stands for the diazo compound of a nitrobenzene sulfonic acid and R stands for an aromatic amine.

4. The process of dyeing organo-oxy-cellulose compounds which comprises applying thereto dyestufis of the type RN:N-R' in which RN:N stands for the diazo derivative of an acid substituted aromatic nitro compound and R stands for a naph- WALTER DUISBERG. WINFRIED HENTRICH. 

